It has been known to use metal oxides, and especially iron oxides, to remove sulfur compounds, such as hydrogen sulfide, carbonyl sulfide, and mercaptans, from fluids, and in particular various liquids, such as water and hydrocarbon liquids. It has also been known to try and increase the reactivity of the iron oxides with the sulfur compounds by adding a catalyst or activator thereto. Most catalysts and activators, however, are solid and have to be physically mixed in with the iron oxide, which can be cumbersome and difficult in pre-existing iron oxide beds. The catalysts and activators often cannot be added to the liquid or fluid being treated by the iron oxide. Further, most catalysts and activators have to be added at a specific point for the reaction to occur. What this means is that most activators or catalyst must be added to the metal oxide prior to contact with the contaminant, not at any point so long as the metal oxide, activator, and sulfur compound contaminant contact each other. Thus, it is desired to have an activator that increases the reactivity of the metal oxide, and especially iron oxide or zinc oxide, and can be added to either the metal oxide, the fluid being treated, or a fluid metal oxide composition so that the fluid and metal oxide are in contact and the activator is then added.
Sulfur removal beds made of metal oxide, especially iron oxide, have traditionally had a fairly limited bed life, so that more than trace amounts of the sulfur compounds break through the iron oxide bed the usefulness of the bed is terminated. In other words, when more than trace amounts of the sulfur compounds pass through the iron oxide bed without reacting with the iron oxide bed material the life of the iron oxide bed is terminated and the iron oxide in the bed must be replaced. Keep in mind that sulfur breakthrough typically involves more than trace amounts of sulfur compounds and that breakthrough occurs even though there is a large amount of unreacted metal oxide that could react with the sulfur compounds and prevent breakthrough. Replacement of the metal oxide or iron oxide bed material can be expensive and a difficult procedure to perform. As such, it is desired to have a method or composition for increasing the reactivity rate between the metal oxide and the sulfur compounds, so that the metal oxide bed life can be extended. It is especially desired to have a method or composition that can be added to the metal oxide and that ensures a greater amount of metal oxide will be reacted before breakthrough.
Methods for increasing the reactivity of the metal oxide bed with the sulfur compounds to prevent breakthrough are known and have included the addition of oxygen or air to the metal oxide bed or heating the metal oxide bed to temperatures greater than 500.degree. Celsius (C). The addition of oxygen or air is disadvantageous because the oxygen is highly reactive and can be dangerous. Heating the metal oxide is also disadvantageous because it is relatively expensive to heat the metal oxide bed and the heated metal oxide bed can also be dangerous because of the high temperatures involved. It would be beneficial to have a method or composition which could be used to increase the reactivity of metal oxides with sulfur compounds, especially in metal oxide beds where breakthrough of the sulfur compounds has occurred. It is also desirable to have a method or composition that initially increases the reaction rate between the metal oxide and sulfur compounds so that the metal oxide bed life can be prolonged. Thus, it would be desirable to have an activator that is safe and can be easily used, and that ensures that the majority of the metal or iron oxide in a reactor bed has reacted with the sulfur compounds.
Finally, it has been unknown to use ethoxylated fatty amines to activate metal oxides and increase the rate of reactivity between the metal oxides and the sulfur compounds. In particular it has been unknown to use ethoxylated fatty amines to activate iron oxide beds used in the removal of sulfur compounds from fluids, especially liquids. Other activators are known to be used in combination with iron oxide compositions, but the use of an ethoxylated fatty amine as an activator to increase reactivity between a metal oxide and reactive sulfur species is unknown. The use of an ethoxylated fatty amine to increase a metal oxide bed's reactivity is unknown.